The present invention relates to semiconductor materials, more particularly to methods and systems for doping or otherwise changing the physical character of semiconductor materials.
Conventional doping methodologies include (i) ion implantation, (ii) diffusion, and (iii) incorporating dopant atoms during the semiconductor growth. Ion implantation is typically carried out using a dedicated implanter that accelerates ionized dopant species toward the semiconductor material, with energies typically in the 100-1000 keV range. Diffusion is typically accomplished using a high temperature furnace, with either a gas source or a solid source for the dopants; the high temperatures allow dopants to diffuse into the material.
Ion implantation, diffusion and similar processes have been limitedly successful in doping wide bandgap materials, including zinc oxide (ZnO), diamond and others. These conventional approaches have not enjoyed complete success for some modern electronic materials because of defect production and/or poor site activation. Ion implantation is an inherently destructive process, creating significant damage in the target material lattice, which must be annealed to produce a quality material. Several materials (silicon carbide, diamond, etc.) anneal at extraordinarily high temperatures, thus making an ion implantation process difficult and costly. Diffusion can be difficult due to the high thermal requirements of certain materials. In addition, defects in materials such as ZnO can lead to self-compensation.
It is therefore desirable in the semiconductor and related arts to devise a doping methodology that is not intrinsically destructive. This quality of non-destructiveness could have a significant positive impact on several industries, including high power electronics, solid state lighting, ultraviolet (UV) light detection, and transparent coatings.